package spen;

// by Evan X. Merz
// www.thisisnotalabel.com

// Example Wav file input and output
// this was written for educational purposes, but feel free to use it for anything you like
// as long as you credit me appropriately ("wav IO based on code by Evan Merz")

// if you catch any bugs in this, or improve upon it significantly, send me the changes
// at evan at thisisnotalabel dot com, so we can share your changes with the world

import java.io.DataInputStream;
import java.io.DataOutputStream;
import java.io.FileInputStream;
import java.io.FileOutputStream;

public class wavIO {
/*
     WAV File Specification
     FROM http://ccrma.stanford.edu/courses/422/projects/WaveFormat/
    The canonical WAVE format starts with the RIFF header:
    0         4   ChunkID          Contains the letters "RIFF" in ASCII form
                                   (0x52494646 big-endian form).
    4         4   ChunkSize        36 + SubChunk2Size, or more precisely:
                                   4 + (8 + SubChunk1Size) + (8 + SubChunk2Size)
                                   This is the size of the rest of the chunk
                                   following this number.  This is the size of the
                                   entire file in bytes minus 8 bytes for the
                                   two fields not included in this count:
                                   ChunkID and ChunkSize.
    8         4   Format           Contains the letters "WAVE"
                                   (0x57415645 big-endian form).

    The "WAVE" format consists of two subchunks: "fmt " and "data":
    The "fmt " subchunk describes the sound data's format:
    12        4   Subchunk1ID      Contains the letters "fmt "
                                   (0x666d7420 big-endian form).
    16        4   Subchunk1Size    16 for PCM.  This is the size of the
                                   rest of the Subchunk which follows this number.
    20        2   AudioFormat      PCM = 1 (i.e. Linear quantization)
                                   Values other than 1 indicate some
                                   form of compression.
    22        2   NumChannels      Mono = 1, Stereo = 2, etc.
    24        4   SampleRate       8000, 44100, etc.
    28        4   ByteRate         == SampleRate * NumChannels * BitsPerSample/8
    32        2   BlockAlign       == NumChannels * BitsPerSample/8
                                   The number of bytes for one sample including
                                   all channels. I wonder what happens when
                                   this number isn't an integer?
    34        2   BitsPerSample    8 bits = 8, 16 bits = 16, etc.

    The "data" subchunk contains the size of the data and the actual sound:
    36        4   Subchunk2ID      Contains the letters "data"
                                   (0x64617461 big-endian form).
    40        4   Subchunk2Size    == NumSamples * NumChannels * BitsPerSample/8
                                   This is the number of bytes in the data.
                                   You can also think of this as the size
                                   of the read of the subchunk following this
                                   number.
    44        *   Data             The actual sound data.


NOTE TO READERS:

The thing that makes reading wav files tricky is that java has no unsigned types.  This means that the
binary data can't just be read and cast appropriately.  Also, we have to use larger types
than are normally necessary.

In many languages including java, an integer is represented by 4 bytes.  The issue here is
that in most languages, integers can be signed or unsigned, and in wav files the  integers
are unsigned.  So, to make sure that we can store the proper values, we have to use longs
to hold integers, and integers to hold shorts.

Then, we have to convert back when we want to save our wav data.

It's complicated, but ultimately, it just results in a few extra functions at the bottom of
this file.  Once you understand the issue, there is no reason to pay any more attention
to it.


ALSO:

This code won't read ALL wav files.  This does not use to full specification.  It just uses
a trimmed down version that most wav files adhere to.


*/

    // our private variables
    private String myPath;
    private long myChunkSize;
    private long mySubChunk1Size;
    private int myFormat;
    private long myChannels;
    private long mySampleRate;
    private long myByteRate;
    private int myBlockAlign;
    private int myBitsPerSample;
    private long myDataSize;

    public long getMySampleRate() {
        return mySampleRate;
    }

    public long getMyChannels() {
        return myChannels;
    }// I made this public so that you can toss whatever you want in here
    // maybe a recorded buffer, maybe just whatever you want

    public long getMyDataSize() {
        return myDataSize;
    }

    public int getMyBitsPerSample() {
        return myBitsPerSample;
    }

    public byte[] myData;

    // get/set for the Path property
    public String getPath() {
        return myPath;
    }

    public void setPath(String newPath) {
        myPath = newPath;
    }

    public void setMyData(byte[] myData) {
        this.myData = myData;
    }

    public void setMyDataSize(long myDataSize) {
        this.myDataSize = myDataSize;
    }

    public void setMyFormat(int myFormat) {
        this.myFormat = myFormat;
    }

    public void setMyPath(String myPath) {
        this.myPath = myPath;
    }

    public void setMyChunkSize(long myChunkSize) {

        this.myChunkSize = myChunkSize;
    }

    public void setMySubChunk1Size(long mySubChunk1Size) {
        this.mySubChunk1Size = mySubChunk1Size;
    }

    public void setMyChannels(long myChannels) {

        this.myChannels = myChannels;
    }

    public void setMySampleRate(long mySampleRate) {

        this.mySampleRate = mySampleRate;
    }

    public void setMyBitsPerSample(int myBitsPerSample) {
        this.myBitsPerSample = myBitsPerSample;
    }

    public void setMyByteRate(long myByteRate) {
        this.myByteRate = myByteRate;
    }

    public void setMyBlockAlign(int myBlockAlign) {
        this.myBlockAlign = myBlockAlign;
    }////

    // / / / / empty constructor
    public wavIO() {
        myPath = "";
    }

    // constructor takes a wav path
    public wavIO(String tmpPath) {
        myPath = tmpPath;
    }

    // read a wav file into this class
    public boolean read() {
        DataInputStream inFile = null;
        myData = null;
        byte[] tmpLong = new byte[4];
        byte[] tmpInt = new byte[2];

        try {
            inFile = new DataInputStream(new FileInputStream(myPath));

            //System.out.println("Reading wav file...\n"); // for debugging only

            String chunkID = "" + (char) inFile.readByte() + (char) inFile.readByte() + (char) inFile.readByte() + (char) inFile.readByte();

            inFile.read(tmpLong); // read the ChunkSize
            myChunkSize = byteArrayToLong(tmpLong);

            String format = "" + (char) inFile.readByte() + (char) inFile.readByte() + (char) inFile.readByte() + (char) inFile.readByte();

            // print what we've read so far
            //System.out.println("chunkID:" + chunkID + " chunk1Size:" + myChunkSize + " format:" + format); // for debugging only


            String subChunk1ID = "" + (char) inFile.readByte() + (char) inFile.readByte() + (char) inFile.readByte() + (char) inFile.readByte();

            inFile.read(tmpLong); // read the SubChunk1Size
            mySubChunk1Size = byteArrayToLong(tmpLong);

            inFile.read(tmpInt); // read the audio format.  This should be 1 for PCM
            myFormat = byteArrayToInt(tmpInt);

            inFile.read(tmpInt); // read the # of channels (1 or 2)
            myChannels = byteArrayToInt(tmpInt);

            inFile.read(tmpLong); // read the samplerate
            mySampleRate = byteArrayToLong(tmpLong);

            inFile.read(tmpLong); // read the byterate
            myByteRate = byteArrayToLong(tmpLong);

            inFile.read(tmpInt); // read the blockalign
            myBlockAlign = byteArrayToInt(tmpInt);

            inFile.read(tmpInt); // read the bitspersample
            myBitsPerSample = byteArrayToInt(tmpInt);

            // print what we've read so far
            //System.out.println("SubChunk1ID:" + subChunk1ID + " SubChunk1Size:" + mySubChunk1Size + " AudioFormat:" + myFormat + " Channels:" + myChannels + " SampleRate:" + mySampleRate);

            // read the data chunk header - reading this IS necessary, because not all wav files will have the data chunk here - for now, we're just assuming that the data chunk is here
            String dataChunkID = "" + (char) inFile.readByte() + (char) inFile.readByte() + (char) inFile.readByte() + (char) inFile.readByte();

            inFile.read(tmpLong); // read the size of the data
            myDataSize = byteArrayToLong(tmpLong);

            // read the data chunk
            myData = new byte[(int) myDataSize];
            inFile.read(myData);

            // close the input stream
            inFile.close();
        }
        catch (Exception e) {
            return false;
        }

        return true; // this should probably be something more descriptive
    }

    public byte[] getMyData() {
        return myData;
    }

    public String getMyPath() {
        return myPath;
    }

    public int getMyFormat() {
        return myFormat;
    }

    public long getMyByteRate() {
        return myByteRate;
    }

    public int getMyBlockAlign() {
        return myBlockAlign;
    }

    public long getMySubChunk1Size() {
        return mySubChunk1Size;
    }

    public long getMyChunkSize() {
        return myChunkSize;
    }// write out the wav file

    public boolean save() {
        try {
            DataOutputStream outFile = new DataOutputStream(new FileOutputStream(myPath));

            // write the wav file per the wav file format
            outFile.writeBytes("RIFF");                    // 00 - RIFF
            outFile.write(intToByteArray((int) myChunkSize), 0, 4);        // 04 - how big is the rest of this file?
            outFile.writeBytes("WAVE");                    // 08 - WAVE
            outFile.writeBytes("fmt ");                    // 12 - fmt
            outFile.write(intToByteArray((int) mySubChunk1Size), 0, 4);    // 16 - size of this chunk
            outFile.write(shortToByteArray((short) myFormat), 0, 2);        // 20 - what is the audio format? 1 for PCM = Pulse Code Modulation
            outFile.write(shortToByteArray((short) myChannels), 0, 2);    // 22 - mono or stereo? 1 or 2?  (or 5 or ???)
            outFile.write(intToByteArray((int) mySampleRate), 0, 4);        // 24 - samples per second (numbers per second)
            outFile.write(intToByteArray((int) myByteRate), 0, 4);        // 28 - bytes per second
            outFile.write(shortToByteArray((short) myBlockAlign), 0, 2);    // 32 - # of bytes in one sample, for all channels
            outFile.write(shortToByteArray((short) myBitsPerSample), 0, 2);    // 34 - how many bits in a sample(number)?  usually 16 or 24
            outFile.writeBytes("data");                    // 36 - data
            outFile.write(intToByteArray((int) myDataSize), 0, 4);        // 40 - how big is this data chunk
            outFile.write(myData);                        // 44 - the actual data itself - just a long string of numbers
        }
        catch (Exception e) {
            System.out.println(e.getMessage());
            return false;
        }

        return true;
    }

    // return a printable summary of the wav file
    public String getSummary() {
        //String newline = System.getProperty("line.separator");
        String newline = "<br>";
        String summary = "<html>Format: " + myFormat + newline + "Channels: " + myChannels + newline + "SampleRate: " + mySampleRate + newline + "ByteRate: " + myByteRate + newline + "BlockAlign: " + myBlockAlign + newline + "BitsPerSample: " + myBitsPerSample + newline + "DataSize: " + myDataSize + "</html>";
        return summary;
    }

// ===========================
// CONVERT BYTES TO JAVA TYPES
// ===========================

    // these two routines convert a byte array to a unsigned short

    public static int byteArrayToInt(byte[] b) {
        int start = 0;
        int low = b[start] & 0xff;
        int high = b[start + 1] & 0xff;
        return (int) (high << 8 | low);
    }


    // these two routines convert a byte array to an unsigned integer
    public static long byteArrayToLong(byte[] b) {
        int start = 0;
        int i = 0;
        int len = 4;
        int cnt = 0;
        byte[] tmp = new byte[len];
        for (i = start; i < (start + len); i++) {
            tmp[cnt] = b[i];
            cnt++;
        }
        long accum = 0;
        i = 0;
        for (int shiftBy = 0; shiftBy < 32; shiftBy += 8) {
            accum |= ((long) (tmp[i] & 0xff)) << shiftBy;
            i++;
        }
        return accum;
    }

// ===========================
// CONVERT JAVA TYPES TO BYTES

    // ===========================
    // returns a byte array of length 4

    private static byte[] intToByteArray(int i) {
        byte[] b = new byte[4];
        b[0] = (byte) (i & 0x00FF);
        b[1] = (byte) ((i >> 8) & 0x000000FF);
        b[2] = (byte) ((i >> 16) & 0x000000FF);
        b[3] = (byte) ((i >> 24) & 0x000000FF);
        return b;
    }

    // convert a short to a byte array
    public static byte[] shortToByteArray(short data) {
        return new byte[]{(byte) (data & 0xff), (byte) ((data >>> 8) & 0xff)};
    }

}